The primary goal of this application is to foster the development of Dr. Daniel Livorsi as an independent VHA investigator devoted to improving antimicrobial-prescribing across the continuum of healthcare. This application specifically focuses on optimizing the performance of antimicrobial stewardship programs (ASPs) in resource-limited settings. ASPs are hospital-based programs that ensure patients receive the right antimicrobial at the right dose and for the right duration. These programs have proven benefits, such as improving patient safety and reducing antimicrobial resistance. ASPs are now mandated in every VHA facility and will soon be required in non-VHA hospitals as well. The widespread implementation of robust ASPs is essential for addressing the crisis of antimicrobial resistance. Though necessary, widespread ASP implementation will be challenging. Many ASPs lack access to Infectious Disease (ID) specialists?including 23% of VHA-ASPs?and it is unclear how ASPs can be effective in such resource-limited settings. This application will begin to address this problem through an ambitious but achievable Research Plan. Project 1 will analyze antimicrobial use data from across the VHA. Multivariable analysis will be used to identify structural and process factors associated with optimal facility-level ASP performance, as measured by facility antimicrobial usage (primary outcome) and 7 secondary metrics. The goal is to identify processes that work for ASPs even in the absence of ID pharmacists and ID physicians. Facilities will also be ranked on the risk-adjusted primary outcome; high and low performers will be identified. Project 2 will use qualitative research methods to determine provider attitudes and organizational factors that impede or foster antimicrobial stewardship at 8 VHA hospitals with ASPs lacking ID support. For this project, the team will conduct research at 4 low-performing and 4 high-performing facilities, as determined by performance on the primary outcome. Project 3 will synthesize the findings from Projects 1 and 2 to develop pilot improvement strategies for low-performing ASPs that lack ID support. The model of Physician Mentored Implementation will guide this intervention, and a pretest-posttest design will be used to assess the effect of the intervention at the 2 intervention hospitals compared to 2 control hospitals. In addition to the above Research Plan, this application proposes integrated Career Development activities that build on Dr. Livorsi?s expertise in leading ASPs and his prior experience with qualitative assessments and secondary data analysis. These career development activities have the following objectives: 1) gaining fluency in the analysis of national VHA databases and the use of multilevel regression models; 2) building expertise in implementation science with a focus on qualitative assessments; and 3) developing proficiency in the conduct and analysis of multicenter interventions. These Research and Career Development plans will prepare Dr. Livorsi for submitting an Investigator-Initiated Research proposal focused on refining existing stewardship metrics. In addition, this work will set the stage for future investigations into evaluating and implementing stewardship processes in other healthcare settings, including ambulatory clinics, emergency rooms, and Community Living Centers.